msem-instigator

When Horn of Seasons enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equipped creature gets +3/+0.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Flying
When Hostile Barbfly enters, you may have it consume. When you do, target creature gets -2/-2 until end of turn. (To consume, sacrifice another creature or exile a creature card from your graveyard.)

Other Wolves and Werewolves you control get +1/+1.
Whenever Hungering Howlpack or another Wolf or Werewolf you control enters, you gain 2 life.

When Hunter's Arsenal enters, create a Weapon token. (It's an Equipment artifact with “Equipped creature gets +1/+1” and equip {2}.)
{1}, {T}, Sacrifice Hunter's Arsenal: Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Idyllic Oasis enters tapped unless you control a Plains.
{T}: Add {G} or {U}.

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. Mill three cards.

Exile target creature or enchantment. You gain 3 life.

When Incantation Demon enters, return target instant or sorcery card from your graveyard to your hand.
Cycling {2} ({2}, Discard this card: Draw a card.)

Menace
Ward—Pay 3 life.
When Infernal Direwolf enters, it fights up to one target creature an opponent controls. Excess damage Infernal Direwolf deals this way is dealt to that creature's controller instead.

Infernal Flames deals 3 damage to target player or planeswalker.
Tether (Then if you cast this from your hand, you may exile it tethered to a creature you control. When it dies, you may cast this from exile without paying its mana cost.)

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
{8}{G}, Exile Influence of Kruphix from your graveyard: Return up to two target cards from your graveyard to your hand.

Indestructible
At the beginning of each player's upkeep, target permanent you control gains protection from everything until end of turn. Then if you control at least five permanents whose colors are exactly different color triads, you win the game.

Exile the top two cards of your library. Until the end of your next turn, you may play those cards. If this spell was cast from a graveyard, you may play cards this way without paying their mana costs.
Flashback {5}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Return up to two target instant and/or sorcery cards from your graveyard to your hand. Exile Intense Revelation.

Other Vampires you control get +1/+1.
Whenever Irascible Bloodwitch or another Vampire enters under your control, Irascible Bloodwitch deals 1 damage to any target.

Flying, trample, lifelink

Indestructible
As long as your devotion to red and white is less than seven, Iroas isn't a creature.
Other creatures you control have first strike.
Whenever you attack for the first time each turn, untap all other creatures you control. After this phase, there is an additional combat phase.

Menace (This creature can't be blocked except by two or more creatures.)
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Jagged Cairn enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}, {T}, Sacrifice Jagged Cairn: Draw a card.

Enchant creature
Enchanted creature gets +3/+3, has flying, and “{1}{W}: Put a +1/+1 counter on this creature.”

Flying
Once during each of your turns, for each creature you control, you may activate one of that creature's activated abilities with {T} in its cost without paying {T} and as though that creature had haste.

Vigilance
{1}{W}: Jhessian Cavalier gains lifelink until end of turn.

Choose two —
• Jund Command deals 3 damage to each non-Dragon creature.
• Jund Command deals 4 damage to each opponent.
• Each opponent sacrifices a planeswalker.
• Mill five cards. Return a permanent card milled this way to your hand.

Menace
Swampcycling {1}, forestcycling {1} ({1}, Discard this card: Search your libary for a Swamp or Forest card, reveal it, put it into your hand, then shuffle.)